Ionic Bonding Test Flashcards
What is the meaning of the term “chemical compound”/
a substance composed of the atoms of two or more elements that are
connected to each other through chemical bonds.
What are some general physical properties of ionic compounds?
tend to exist as solids.
tend to have high melting points.
tend to be good conductors of electrical current when they are in the liquid
(molten) state.
What are some general physical properties of molecular compounds?
tend to have lower melting points than do ionic compounds.
tend to be gases, liquids, or low melting point solids.
tend to be nonconductors of electrical current when they are in the liquid (molten) state.
What is the meaning of the term “chemical bond”?
the attractive force that holds two atoms together
What is the meaning of the term “ionic bond”?
a chemical bond formed through the transfer of one or more electrons from one
atom or group of atoms to another.
What is the meaning of the term “covalent bond”?
the chemical bond formed through the sharing of one or more pairs of electrons
between two atoms.
What is a more “realistic” description of the relationship between ionic and covalent bonds?
Most chemical bonds have some degree of both ionic character and covalent character.
What forces of attraction exist between two atoms (like hydrogen) that are close to one another?
There is an attractive force that exists between the nucleus of each atom and the electron cloud of
its neighbor atom.
What forces of repulsion exist between two atoms (like hydrogen) that are close to one another?
There is a repulsive force that exists between the electron cloud of on atom and the electron cloud
of its neighbor atom, as well as between the nucleus of one atom and the nucleus of its neighbor atom.
When two atoms settle into a bond, what is the relationship between the forces of attraction and the
forces of repulsion that exist between those two atoms?
In a stable bond, there is a balance between the forces of attraction and the forces of repulsion.
Why is it only the outer electrons of an atom that are most likely to be involved in the chemical
bonding process and not the inner electrons?
The inner electrons are “shielded” from interaction by the presence of the outer electrons.
What is a valence electron?
an electron in the outermost electron shell
always found in either the “s” and “p” subshells
What is a Lewis Symbol?
the chemical symbol of an element surrounded by dots equal in number to the
number of valence electrons present in atoms of that element.
What is an electron dot structure?
same thing as a Lewis Structure
When drawing the Lewis dot symbol for an atom, what condition must be true for valence electrons
to be placed in pairs?
There must be at least one electron on each side of the chemical symbol before a pair is made.
For the representative elements, what is the relationship between the group number of an element
and the number of valence electrons present in an atom of that element?
For elements in groups 1 and 2, the number of valence electrons is equal to the group number. For
elements in groups 13 through 18, the number of valence electrons is equal to the group number
minus ten.
For the representative elements, what is the maximum number of valence electrons that can be
present in an atom?
8
What is the meaning of the term “stable”?
does not undergo spontaneous change
How are the noble gases different from other elemental gases like oxygen and hydrogen?
they are more stable
What common feature of the noble gases is thought to be the primary cause of their chemical
stability?
completely filled s and p shells
What is the “Octet rule”?
the atoms of elements lose, gain, or share
electrons to produce a noble gas configuration
Although helium is a noble gas, it is not fully compliant with the octet rule. Why is this?
Since helium only has two electrons, it cannot have an octet of valence electrons. Instead, it has
only two valence electrons.
What is an “ion”?
an atom that is electrically charged as a result of loss or gain of electrons
Why does the electrical charge on an atom change when it loses or gains electrons?
there are more positive or negative charges, resulting in either an overall positive or negative charge
What is an anion?
an atom that gains electrons and therefore has a negative charge
How is an anion formed?
when a neutral atom acquires one or more electrons from another atom.
What is a cation?
an atom that loses electrons and therefore has a positive charge
Why are the chemical properties of an anion or a cation different from those of its parent atom?
an ion has a different electron configuration (fewer or more electrons) than the atom from which it is formed, so it has different chemical properties as well.
Any time that there is an anion formed, there must also be formed a cation. Why is this so?
The total number of electrons lost by the atom of one element must be equal to
the total number of electrons gained by the atom of the other element. Thus, positive and negative
ions must always be formed at the same time.
What is an ionic bond?
the chemical bond that is the result of the attraction of positive ions (cations) and negative ions (anions) to each other
How is an ionic bond formed?
electron transfer
What is the origin of the force that holds the ions together?
Objects of opposite charges are drawn toward each other
Are these cations or anions?
Na+
Cl2-
Ne4+
cation
anion
cation
Why do atoms tend to lose or acquire electrons until they have achieved a noble gas electron
configuration?
It allows them to become more stable
Why do atoms in groups 1, 2, and 3 of the periodic table tend to lose electrons when forming ions
it is more energetically favorable
What is the meaning of the term “isoelectronic species?”
ions with the same number of electrons in the same electron configuration
When an atom loses or acquires electrons so as to be isoelectronic with a noble gas, it is not
actually transformed into being that noble gas. Why is this true?
The number of protons in the nucleus of the
isoelectronic ion is different than the number of protons present in the noble gas that it is
isoelectronic with.
What is a Lewis structure?
grouping of Lewis Symbols that shows either the transfer of electrons or the
sharing of electrons in chemical bonds.
What kinds of elements tend to be present in ionic compounds?
combination of metals and nonmetals
What kinds of elements tend to be present in covalent compounds?
only nonmetals
With respect to the process of electron transfer, why are ionic compounds always electrically
neutral?
electron loss is always equal to electron gain
When writing the chemical formula of an ionic compound, what order is used with respect to the
placement of the anion and the cation?
In an ionic compound, the formula of the cation is written first and then the formula of the anion is
written second.
What is the purpose of the subscripts in a chemical formula such as Na2O?
provide the combining ratio
How are the anions and cations found in ionic compounds arranged?
cations first
What is a monoatomic ion?
an ion formed by a single atom that has lost or gained electrons.
What is a polyatomic ion?
an ion formed by a group of atoms that have lost or gained electrons.
Polyatomic ions are very stable species, generally maintaining their _____
during chemical reactions
identities
What kind of chemical bonding is present in polyatomic ions?
covalent bonds
What happens to polyatomic ions during chemical reactions?
they maintain their identities
When are polyatomic ions found alone?
never
What is the relationship between polyatomic ions and chemical compounds?
polyatomic ions are pieces of chemical compounds
